Speed change mechanism



Nov. 10, 1931. J. R. RlcHER 1,831,577

SPEED CHANGE MECHANISM l Filed sept. s, 195o i191. Jg i llmmmllluf/wrm..

mately along the line Parenteel Nov. 10, 1931 JOSEPH R. RIGHER, oF oAxPARK, ILLINOIS SPEED CHANGE MEcmNIsi/r The invention relates generallyto speed changemechanisms and more particularly to a speed reducingmechanismv ofnovel and compact construction.

The genera] object of the invention isto provide a new and improved'speed change mechanism which is simple in construction and elicient inoperation.

Another object is to provide an improved speed change mechanismembodying rolling contacts exclusively so as to -eliminate frictionbetween parts. i

A further Objectis to provide a novel speed change mechanism compact inconstruction so that it can be readily mounted on one end cfafractional'horse-power electric motor. j

Fig. 1 is an elevational view, partly in section along the line 1-1 ofFig. 2, of a pref ferred form of the invention applied to a fractionalhorse-power motor.

Fig. 2 is a transverse section approximately along the line 2 2 of Fig.1.`

Fig. 3 is a fragmentary view approxi- 3-3 of Fig. 2.

While I have shown in the drawings. and shall herein describe in detailthe preferred embodiment of my invention, it is to be understood that Ido not thereby intend to limit the invention to the specific formdisclosed, but aim to cover all modilications and alternativeconstructions falling within the spirit and scope of the invention asexpressed in the appended claims. n

In the form chosen for purposes 'of disclosure the invention isillustratedin connection with an electric motor 1 having a stator frame2. An end bell or housing 3 is secured to one end of the stator frameand is provided with suitable feet' ll. This housing also has a bearingdesignated generally as 5 for one end of a rotor shaft 6, the other endof which normally extends through a similar O housing on the other endof the stator frame and has a projecting end 7 adapted to receiveVtuted'on the pulley of the casing and Application led September 6,'1930. Serial No. 480,063.

a pulley or coupling device. In combining the preferred form of myinvention with such a motor however, a special housing 8 is substiend ofthe stator frame v2, this housing also having feet f1 and a bearing 9for the driving end of -the shaft, the normal pulley shaftextension 7extending beyond said bearingA as indicated clearly in Fig; 1 to providea driving means for the speed change mechanism. i

`The speed change mechanism is herein 'disclosed positioned within atubular casing 10 which is secured to the housing 8, and an end plate orclosure 11 which closes thev outerlend hasa bearing 12 in which a drivenshaft 13 is rotatably mounted in axial alinement with the drivingshaft.A

As illustrated in the drawingsthe mechanism connecting the'driving shaft`6 and the driven shaft 13 embodies an 'eccentric device v14: ,on thedriving shaft which eccentric device comprises an eccentric 15 connectedto the shaft 6, a ball bearing'l having` its inner race secured to theeccentric and a ring 17 secured to the outerrace. Thus the ring`17 whichforms the periphery of the eccentric device is freely rotatable relativeto the driving shaft 6. v l

The driven shaft`13l preferably has a portion or member 18formedintegrally with its inner end, a ball bearing 19 being positionedwith its inner race on the adjacent end of the driving shaft 6 and itsouter race securedin a recess in the portion 18. A somewhat simi- -la-rmember 20 is mounted in spaced relation to the portion 18 longitudinallyof the shaft 6 and is supported rotatably on said shaft by a ballbearing 21. The members 18 and 2O as disclosed herein have a pluralityof out wardly extending arms 22, corresponding arms of the two membersbeing connected by headed pivot pins 23 having nuts 24 thereon. n eachpivot pin 23 is hinged a link 25 shown in detail in Fig. 3, the free endof eachlink 'carrying 'a roller 26 'which is rotatably suphaving teethformed by substantially 4cylinported on a pin 27 secured between arms 28on the link.

The rollers 26 as shown most clearly in Fig. 2, run on the ring 17 ofthe eccentric device and during operation of the mechanism are adaptedto roll into and out of a plurality of depressions 29 forming aninternal toothed device on an inwardly extending flange 30 of the casingl0. In the exemplary form of the invention the depressions havesubstantially cylindrical surfaces with a radius approximately lfiftypercentgreater than the diameter ofthe-rollers 26,'theie beingsixirollers and twenty-three depressions. Thus the dei5 pressions equalin number, an even number times the number of rollers, -minus one, toprovide a speed ratio of 23 to l between the shafts 6 and 13.

The pivoted links serve as a means for mounting the rollers movably onthe driven ymember sand operate-*to constrain Vthe driven 1member tomove with the rollers through their ,generally circular path. les thedriving shaft -operates -the eccentric `device rolls Silthefrollersinto.and-out-ofthe depressions and .overthe teeth formedbetween.theidcpressions and `since the dri-ven `shaft is .thereby turned.through `.one depression for each 'complete revolution. ofthe.eccentric device -it is evident f that the driven shaft will rotate atone twenty-.third `the speed of .the driving shaft andin the samedirectionasthe driving shaft.

The housing 8 as illustratedherein haszan send .Wall lfandfisprovidedwith aplurality 35 ,ofzair ducts 132 soas 4topermit proper ventilationof the motor. AThe 1parts 2, .3, 8 and 10 are 4fastenedtogether by aplurality-of longitudinally extending bolts-33 having icollars 3 4:pinned-thereto .andiitting into recesses 85 di in the casing `10,suitable nuts 3 6 being rprovided on .the other .ends to secure .theparts 2, 3, 8 and 1 0 together. These bolts .project through aperturesin the closure ,11 and .receive ynuts 37 forfsecuriiig the ,closure .tothe 4'" casing. 'Thus When the nuts are removed it closure and liavinga,recessin its inner end carrying a 'ball .bearing for theadjaceut end ofthe motor shaft, and means for driving the driven ,member from the shaftof the motor and yin the same direction kof rotation "I" comprising aplurality of ,longitudinally extending c'ircumferentially spaced pivotpins on the inner end lof said driveninember. links 'hinged-on saidpivot :pins `and having rollers on their free-ends, ymeans Withinsai-:leasing drically surfaced depressions and over Which said rollersoperate and an eccentric adapted to be supported on and driven by theshaft of the motor for moving said rollers over said teeth.

2. A speed change mechanism comprising, in combination, a casing,driving and driven members rotatably mounted in axial alineinent in saidcasing, a plate secured to the inner end of the driven member andcarrying a plurality of longitudinally extending circumferentiallyspaced -pivotpins, a secondfplate 'rotatably mounted on'tlie drivingshaft and connected to the free ends of said pins, an eccentric deviceon said driving shaft intermediate said plates, an internal ring gearsurrounding said eccentric device outsideof saidpins, a plurality oflinks hinged on said pivot `pinsand rollers on said links operable overthe teeth of said gear by said eccentric device.

3. A speed change .mechanism comprising, inl combination, :a casing,driving vand-.driven members rotatably mounted `fin :axial alinemeiitinsaid casing, a plurality of longitudinally extendinglcircumferentially spaced pivot pin-s `on' the inner end-of said `drivenmember, a plurality offlinks hinged 'on said pivot pins, an internaltoothed device, roll- -ers :on said :links-operable Aover the Iteeth ofsaid device,and means on said driving member operable to roll saidrollers `over said teeth.

4. lA speed changemechanism comprising,

in combination, a casing, Adriving and driven members rotatably mountedin axial 'alinement in said casing, vmeans onthe inner end of the drivenmember carrying a pluialityof Alongitudinally `extendingcircumferentially overtheteeth onsaid device by said eccentric fdevice.

5. Aspeed change mechanism comprising, 11i combination, a casing,driving-and driven members rotatably `mounted in axial alineinent insaid casing, and means forfdriving said driven member in the sainedirection as the driving member comprising an eccentric device on saiddriving member, a plurality of circumferentially spaced longitudinallyextending pivot pins secured to the .inner end of said driven member,links vmounted on said pivot pins carrying rollers at their free endsoperable on said-eccentric device and an internal Ytoothed device havinga plurality of substantially cylindrically surfaced depressions betweenteeth over Which said rollers operate.

6. A speed ch ange mechanism comprising, incombination, a`casing,'driving g and driven kmeinlieis rotatably mounted in .axialalinement in said casing, and means for driving said driven member inthe same direction as the driving member comprising an eccentric deviceon said driving member, a plurality Y of circumferentially spacedlongitudinally extending rollers disposed about the axis of said shafts,means movably mounted on said driven member and carrying said rollersfor movement substantially radially of said driven member for operationof the rollers on said eccentric device, and an internal toothed devicehaving a plurality of substantially cylindrically surfaced depressionsbetween teeth over Which said rollers operate. In testimony whereof, Ihave hereunto affixed my signature.

JOSEPH R. RICHER.

